This invention relates generally to vibration damping apparatus and more particularly to an active suspension system which is devoid of a natural resonant frequency of vibrational motion.
The vibration behavior of rigid masses exhibits several modes of vibrational motion, each associated with a particular resonant frequency. Methods utilized to reduce the vibration include the use of both active the passive means of isolation. Passive devices include such apparatus as springs and shock absorbers, while active devices include a sensor which senses the motion of the vibrating body and translates this movement into an electrical signal, which is then fed to a driver unit which counteracts the vibrational movement.
Known spring suspensions become weaker in the cross axis directions as their axial stiffness is reduced. Moreover, most mechanical spring suspension characteristics are fixed by their design and construction. Gas springs are known to be adjustable but do not provide radial support without external pressurization, and are unsuitable for certain environments such as the vacuum of outer space.
Accordingly, it is an oject of the present invention to provide an improvement in vibration isolators.
It is another object of the invention to provide an improved single degree of freedom suspension element which can provide a substantially zero natural frequency, thus possessing broadband attenuation characteristics for all higher vibrational frequencies, while still providing physical support in other directions.
And yet a further object of the invention is to provide an electromagnetic vibration isolator having symmetrical control and magnetic centering forces.
And yet another object of the invention is to provide an improved electromagnetic vibration isolator which eliminates frictional effects and which exhibits improved sensitivity.